A simple FM transmitter

Here is a low component count FM transmitter. It sacrifices some features, like the ability to adjust the frequency, for simplicity’s sake. The build method is fairly common with amateur radio but we don’t see it around here too much. Each component gets a 5mm-by-5mm copper clad pad which is super glued to the ground plate as an insulator. There’s even a pictorial example of this method if you need some help with visualization.

One of the schematics included in the article shows how to incorporate a condenser microphone into the unit. We guess that makes it pretty easy to add an FM ‘bug’ to your arsenal of covert listening devices. Just make sure to check your local laws before building and using this. We’re not sure what the FCC would think of it here in America so we’re hoping some well-informed readers will educate us with a comment.

[Thanks Bart]

Condenser microphone building

mic

Browsing around today, this project caught our eye. Mainly due to the visual similarity to, well, personal massagers. As it turns out, it’s a home made studio condenser microphone. We would generally prefer to link directly to his personal page, that has a slightly more in dept write up, but it has popups and pop unders, so enter at your own risk.  Generally condenser mics require phantom power to make the magic happen, but he has included a circuit to run them off of 9v batteries. We’ve done condenser mics before, but this seems a bit quicker and dirtier.